Internal-combustion engine



c. SARGENT Filed June 27, 71919 4 sheetssheet 1 Apr. 10, 1923.

INTERNAL GOMBUSTION ENGIVNE r 1,451,407 c. SARGENT INTERNAL COMBUSTION ENGINE Apn 10, 1923.

, 1919 4 sheets-sheet 2 Filed June 27 Apr. 10, 1923.

CJE. SARGENT INTERNAL COMBUS TION ENGINE 4 sheets-sheet 5 F'd'June 27, 1919 Patented Apr. 10, 1923.

'UNITED STATES INTERNAL-CMBUSTION ENGINE Application filed June 27, 1919, Serial Ne. 307460,

T 0 all whom if may conccrn Be itknown that L CHARLES E. SARGENT, a citizen of the United States, residing at Indianapolis, in the county of Marion and State of Indiana, 'have invented a new and useful Improvement in Internal-Combuston Engines, of which the following is a' specification. i

, My invention' relates to certain new and useful improvementsin internal combustion engines of the Diesel type.

An object of this invention is to provide an improved means for injecting the fueloil into the cylinder so as to get a more intimate nixture of fuel and air whereby the resulting charge will burn more completely and evenly, thereby increasing the efliciency of the engine and decreasing the tendency of carbon to deposit on the walls of the combustion chamber, valves, etc.

This and other objects aswill appear in the following specification are accomplished by my invention which is herein described and covered *by the appended claims.

Referring now to the drawings,

Figure l is a lougitudinal section through one of the cylinders of an engine embodying my invention; Fig. 2 is a, longitudinal section through the fuel pump; Fig. 3 is a sec tion on the line 3 of 2; Fig. 4 is a longitudinal section on the line 4: of Fig. l at right angles to that shown in Fig. l ;"Fig. 5 isa radial section on the line 5 of' Fg. 4:

Fig. 6 is an enlarged section of the top of' the cylinder showing the pressure pistonapproaching the'end of its downward movement; Fig. 7 is a similar section w th the pressure piston up; Fig. '8 is a horizontal section on the line 8 of Fig. 7; and Fig9 is' a diagram showing the positions in which the various movements of a cycle occur.

-The engine hereinillustrated is of the i liquid fuel'type Its novelty lies primarily in the means forintroducing the liquid fuel, and this device can beepplied, if desired, either to two or four cycle engines. `The engine 'here shown is a four-cylinder two-cycle engine, one cylinder only being illustrated,

since that clearly shows the principles of my invention, butthe fuel-pump will be seen to have' connections for feeding fuel to four cylinders.

Referring to the drawings, 10 is the cylnder and 11 the crank-case in which is journaled the crank-shaft '12 havin' disks 13 forming a ly-wheel and connected i y a crank- OFFICE."

CHARLES EsARG ENT, OF INDIANAPOLIS INDIANA.

pin 14: on which is pivoted a pitnan 15 coni nected to the piston 16 through the medium of the usual *wrist-pin 17., The fly-wheel disks 13 are provided with openings 18 (Figf 4) which, as the 'fly-wheel rotates. come into registration with hollow thimbles 19 (Fig. v i

5) extending through the crank-case wall and pressed nwards aganst the fly-wheel disks by springs 20. As is shown by dotted lines in Fg. 4, there aretwo of these thimbles 19 so that the crank-case is connected through one or the other with the atmosphere during the entire rise of the piston. Air thus flows into the crank case from the atmosphere during the entire rise of thepiston as is common in two-cycle engines.

21 (dotted lines Fig.'4) is' the exhau's't and 22 the intake port. Theseports are uncovered by the pisten in' its descent in 'the usual way, their timing being shown on F 9. The exhaust opens at the end of 121 of;

downward movement of the crank, that is 59 from the bottom of the piston-stroke while the intake opens 415 from the, bottom of the stroke. Thus. as the piston descends, the exhaust first opens, permitting the cylinder pressure to fall approximately to atmospheric, and later the intake opens permitting the air compressed in the 'crank case to flow in and scavenge the ,cylinclen 23 isa fuel-pump shaft, which is driven by a worm gear on the main shaft, and'in a two-cycle engine at the same speed. The shaft'has a flat place 24 which operates as a cam to reciprocate the pump-pistonsfz, each of which is inwardly pressed by a spring 26. The fuel comes into a reservoir 27 at the back of the pump, thence through a pump-intake valve 28 into the space above the pump piston. As the piston reciprocates the fuel is forced out through a pump-exhaust 29 into a fuel pipe 29% The timing of the pump cam is that illustrated on the Figure 9; that is the pump-piston moves' in for the first 45 of the second quadrant of the descent of the main pisten and moves pump-piston is stationary, f Thus the fuel delivery occurs when the intake and exhaust valves are both open andthere is therefore no 'necessity for delivering it against high pressure.

For the purpose of delivering the fuel to the engine cylinder at the time when there 34 on the main shaft.. The timing of the pressure piston is shown in Figure 9. The pressure piston starts up 26% from 'the beginning of the second quadrant of the crank circle and reaches the top of' its movement when the crank is -at the bottom of its stroke. Thus it is movin up at the time when the fuel is being delivered and so opa poses no resistance to ts entrance. The stern of the pressure pisten, as has been heretofore stated, is hollow, and is provided with perforations entering its central hollow tangentially, as shown in Figure 8. The position of these perforations 35 is such that when the piston is'up they are uncovered, i 25 asshown in" Figure 7, so that the space under the pressure piston is filled with gas passing up through the stem 31 and out through these perforations. The fuel thus ente'rs an annular space 36 beneath the pressure piston and at a height to register with the perforations 35 when the pressure piston is at its lowest point of movement. The annular space has communication through an opening 37 with the space under the pressure piston. Backward movement of the fuel is preventedby a valve '38. The operation of the fuel-injection will now be readily apparent. As the main piston moves up, compressing the air in the cylinder to the high point desired in engines of this character, that is, approximately 500 pounds to the square inch the space beneath the pressure piston which is filled with burnt gas fills up further with gas and air at considerable pressure 41 before the piston reaches the upper end of its movement, the pressure piston starts down trapping the gas and air beneath it. When the main piston reaches the top of its stroke and is just ready to receive the force of combustion upon it the pressurepiston is nearly at the bottom of its stroke, as shown in Figure 6,

` when the gas and air beneath the piston is compressed to a very high degree above the oil in the annular space. This pressure approximates 1000 pounds to the square inch, and is thus ample to force the fuel into the cylinder against the compression therein.

Just as the crank passes the top of its stroke the pressure pisten moves down far enough to throw the perforations 35 in its hollow stern or nozzle into registration with the an'nular space 36. in which is the oil. The high pressure above the oil instantly forces .it out through the nozzle 31 into the com bustion chamber where it ignites spontane- I ously.. Premature combustion of the fuel in the annular space is prevented by several factors; lst, the gas above it is largely burned gas for the pressure piston starts to move up before the exhaust opens and is well under way before the intake opens; and, 2nd, the Volume of air contained in the space is not suflicient for any very great amount of combustion as only the oxygen on top of the oil in the annular space could ignite in any event; -The tangential arrangement of the perforations 35 causes the oil to enter the nozzle in a whirling form so as to enter the cylinder ina condition to mix as rapidly as possible with the air therein.

The arrangement above described thus produces an engine of the Diesel type which can be made in very small sizes and which possesses the high efliciency of the Diesel engines without the attendant disadvantages of a separate high pressure pump. The fuel pump o'perates at low pressure, driving the oil into an auxiliary chamber which receives gas from the cylinder within when the pressure is raised to an eXtent suflicient that when the communication with the cylinder is again open the oil will enter with the requisite force.

Since the novelty of the present invention inheres in the fuel-feeding means I have not considered it necessary to show parts of my engine which are totally disconnected therewith, as, for instance, starting means, lubricating means, and the like, nor have I illustrated any means for varying the timing of the fuel injection, since these features are known in the art and can be supplied by a v mechanric in the forms-which seem to him, best to Gonform to engineering requisites. It will be evident too that if desired the present arrangement can readily be applied to four-cycle engines, the only change necessary being to drive the pressure pisten cam and fuelpump at half the speed of the main shaft, and to supply the valves usually cmployed in fourcycle engines. These modifications being obvious and within the range of skill of a mechanic but, because of the possibility of making such modifications, I do not intend to limit myself to the specific form herein shown, except as pointed out in the claims, in which -it is my intention to claim all the novelty inclose communication between said cylinders near the end of the compression stroke of the main piston, means for f'o'cing down the prssure piston for conpressing the charge of gas in the pressure cylinder, said tube upon a further movement opening communication between the pressure cylinder and main cylnder through said chamber.

2. In a Diesel-type engine, a cyi inder, a piston therein, a chamber adjacent the cylinder and communicating thereWith, means for supplying a measure charge of fuel to said chamber, an auxiliary cylinder, a pressure piston therein, a passage connecting said cylinders, a hollow tube slidable in said passageway, and connected to said pressure piston for closing communication between said cylinders near the end of the compression stroke of the main piston, means for forcing down the pressure piston for compressing the charge of gas in the pressure cylinder, said tube upon a further movement opening communication between the pressure cyiinder and main cylinder through said chamber.

3. In a Diesel-type engine, a cylinder, a piston therein, a chamber adjacent the cylinder and communicating therewith, means for supplying a measured charge of fuei to said chamber, an auxiliary cylinder, a pressure piston thei-ein, a -passage connecting said cylinders and chamber, an opening connecting the auxiliary cylinder and chamber, a hollow tube connected to said pressure piston and slidable in said passage and normally closing communication between said charnber and cyiinder, openings leading into said hollow tube, and means for moving said pressure piston to close said last named openings and to compress the gas in said auxiliary cylinder, said last named openings registering with the chamber as the pressure piston nears the end of its stroke, Whereby the charge of fuel is 'forced through said hollow tube into the cylinder.

4:. In an internal combust-ion engine, a cylinder, a piston therein, a chamber adjacent said cylinder, means for supplying a measured charge of fuel to said chamber, means for putting said charge under pressure, a passageway between the chamber and cylinder and a sliding valve in said passageway, said valve having a longitudinal passage opening into said cylinder and openings leading tangentialiy into said longitudinal passage whereby the charge is introduced into the cylinder in the form of a Whrling spray. i

CHARLES E. SARGENT. 

